A large database supports the use of simple models of post-fire tree mortality for thick-barked conifers, with less support for other species

Fire Ecology

Table 11 Statistical comparison of AUCs (area under the receiver operating characteristic [ROC] curve) between samples for which percentage crown volume scorched (CVS) was sampled in the field and calculated based on other measurements of canopy injury (e.g., crown length scorch, change in crown ratio, change in canopy base height). We tested for statistical differences in AUCs between first and second fires using the method of DeLong et al. (1988) as modified for the pROC package in the statistical program R to test unpaired ROC curves (Robin et al. 2011). U = generalized U-statistic; R-A = Ryan and Amman model, which can be applied to many species; Pre-fire models predict morality after fire based on predictors available before fire. Data used to evaluate post-fire tree mortality models are from the USA, from fires occurring from 1981 to 2016

Model	Field measurements		Calculated		U	df	P
Model	n	AUC	n	AUC	U	df	P
Abies concolor – R-A	11 621	0.897	572	0.746	7.32	593	<0.001
Abies magnifica – R-A	291	0.885	216	0.634	4.56	275	<0.001
Pinus lambertiana – R-A	2 264	0.903	121	0.826	1.91	126	0.059
Pinus ponderosa – R-A	30 672	0.894	12 468	0.888	1.50	19 575	0.133
Pinus ponderosa – Pre-fire	25 612	0.868	12 467	0.880	−2.47	21 735	0.013
Pseudotsuga menziesii – R-A	14 260	0.894	916	0.880	2.83	22 940	0.005
Pseudotsuga menziesii – Pre-fire	12 687	0.921	916	0.880	8.30	21 617	<0.001